Association of T-Cell Profiles With Disease Severity, Drug-Induced Liver Injury, and Treatment Completion in Tuberculosis

Abstract

Background: Tuberculosis (TB) treatment is challenged by a long duration, poor adherence, and the high risk of drug-induced liver injury (DILI). T-cell immunity is essential for anti-mycobacterial defense, but current immune-monitoring methods poorly reflect disease severity and treatment response. Correlations of immune subpopulations with TB severity, DILI, and treatment prognosis remain poorly understood.

Methods: Peripheral blood mononuclear cells were collected from confirmed TB patients (n = 40). Multiparameter flow cytometry analysis was used to assess previously defined TB-associated T-cell phenotypes based on the co-expression of cytokines and immune checkpoint molecules following stimulation with two Mycobacterium tuberculosis peptides: culture filtrate protein 10 and early secreted antigenic target 6. Patients were subgrouped by disease severity, DILI, and treatment regimen (16-week short course vs. 24-week standard).

Results: Specific subsets (14/124) were found to be associated with disease severity. Notably, six of 14 subsets were positive for programmed death-ligand 1 (PD-L1), indicating its potential role in disease progression. DILI was associated with three interleukin (IL)-21⁺ subsets (naïve CD4⁺, memory CD8⁺, and interferon [IFN]-γ^- CD4⁺ T cells) and IL-17⁺ memory CD8⁺ T cells, along with PD-L1⁺TIM-3⁺CD4⁺ T cells (all p < 0.05). The 16-week and 24-week treatment groups showed a significant difference in IFN-γ⁺ naïve CD8⁺ T cells at week 16 (p = 0.013), but not at treatment completion (p = 0.393), despite the different durations.

Conclusions: This study identifies specific T-cell phenotypes associated with TB severity, DILI, and treatment dynamics, highlighting potential immune markers for disease monitoring and DILI prediction.

Keywords: T‐cell phenotypes; drug‐induced liver injury; immune checkpoint molecules; treatment response; tuberculosis.

FIGURE 1

Flowchart of the enrollment for study participants. Patients with drug‐susceptible tuberculosis and available serum samples from a parent clinical trial were included.

FIGURE 2

Significant intergroup variations in CD4⁺ and CD8⁺ T‐cell phenotypes among tuberculosis patients stratified by clinical characteristics. Proportions of CD4⁺ and CD8⁺ T‐cell phenotypes between patient subgroups stratified by: sputum smear positivity, categorized by bacterial load as negative (−), scantly positive and 1+, or 2+ (a); number of lung lobes involved (≤ 3 or > 3) (b); and number of cavities (0, 1, or ≥ 2) (c). Data analyzed by Kruskal–Wallis test (a, c) or two‐tailed Mann–Whitney test (b); *p < 0.05, **p < 0.01. CTLA‐4: cytotoxic T‐lymphocyte–associated protein 4; IL: interleukin; IFN: interferon; LAG‐3: lymphocyte activation gene 3; PD‐1: programmed death‐1; PD‐L1: programmed death‐ligand 1; TIM‐3: T‐cell immunoglobulin and mucin domain‐containing 3.

FIGURE 3

Impact of sputum smear conversion time on the proportions of CD4⁺ and CD8⁺ T‐cell phenotypes in tuberculosis patients. Proportions of the indicated T‐cell populations among three groups of patients stratified by time to sputum smear conversion: within 1 month (1 M), within 2 months (2 M), and ≥ 3 months (≥ 3 M). Data are presented as means ± standard deviation (SD; vertical error bars), analyzed by Kruskal–Wallis test; *p < 0.05, **p < 0.01. LAG‐3: lymphocyte activation gene 3; PD‐1: programmed death‐1; PD‐L1: programmed death‐ligand 1.

FIGURE 4

Effect of drug‐induced liver injury (DILI) on the proportions of CD4⁺ and CD8⁺ T‐cell phenotypes in tuberculosis patients. Proportions of the indicated T‐cell populations among two groups of patients stratified by no DILI (NO LI) and DILI (LI). Data analyzed by two tailed Mann–Whitney test; *p < 0.05, **p < 0.01. IL: interleukin; IFN: interferon; PD‐L1: programmed death‐ligand 1; TIM‐3: T‐cell immunoglobulin and mucin domain‐containing 3.

FIGURE 5

Impact of treatment regimen and duration on the CD45RO⁻IFN‐γ⁺CD8⁺ T‐cell phenotype in tuberculosis patients. Proportions of CD45RO⁻IFN‐γ⁺ CD8⁺ T‐cells across three groups: 6‐MRG_16weeks (16‐week standard regimen), 4‐MRG_16weeks (16‐week shortened regimen), and 6‐MRG_24weeks (24‐week standard regimen). Data presented as individual values (dots) with group means (horizontal lines) and standard deviations (SDs, error bars), analyzed by two‐tailed Mann–Whitney tests between the 16‐week standard and shortened regimens, and the 16‐week and 24‐week regimens; *p < 0.05. Horizontal lines and error bars denote central tendency and variability, respectively. IFN: interferon; ns: not significant (p > 0.05).